Self-folding materials printed using 3D printer in an experimental project

Self-folding materials printed using 3D printer in an experimental project

Researchers have printed self-folding materials using a 3D printing in an interesting experimental project. Carnegie Mellon University researchers used 3D printer to print some small objects which fold themselves into different shapes when heated. Self-folding materials are cheaper to produce compared to solid 3D objects.

Lining Yao, assistant professor in the Human-Computer Interaction Institute and director of the Morphing Matter Lab informed, “We wanted to see how self-assembly could be made more democratic --accessible to many users.”

While working on project codenamed Thermorph, Yao and her team members successfully created objects that could fold themselves into predetermined shapes, such as a rose, a boat or even a bunny. The results of their research were shared at CHI 2018, the Conference on Human Factors in Computing Systems, April 21-26 in Montreal, Canada.

Molds for boat hulls and other fibreglass products might be inexpensively produced using these materials. The researchers were able to create self-folding structure by using the least expensive type of 3D printer - an FDM printer - and by taking advantage of warpage, a common problem with these printers.

"We believe the general algorithm and existing material systems should enable us to eventually make large, strong self-folding objects, such as chairs, boats or even satellites," said Jianzhe Gu, HCII research intern.

The objects emerge from the 3-D printer as flat, hard plastic. When the plastic is placed in water hot enough to turn it soft and rubbery -- but not hot enough to melt it -- the folding process is triggered.

Though they used a 3-D printer with standard hardware, the researchers replaced the machine's open source software with their own code that automatically calculates the print speed and patterns necessary to achieve particular folding angles.

"The software is based on new curve-folding theory representing banding motions of curved area. The software based on this theory can compile any arbitrary 3-D mesh shape to an associated thermoplastic sheet in a few seconds without human intervention," said Byoungkwon An, a research affiliate in HCII.

"It's hard to imagine this being done manually," Yao said.

Though these early examples are at a desktop scale, making larger self-folding objects appears feasible.

Video Source: Carnegie Mellon University

Thermorph from Morphing Matter Lab on Vimeo.

We develop a novel method printing complex self-folding geometries. We demonstrated that with a desktop fused deposition modeling (FDM) 3D printer, off-the-shelf printing filaments and a design editor, we can print flat thermoplastic composites and trigger them to self-fold into 3D with arbitrary bending angles. This is a suitable technique, called Thermorph, to prototype hollow and foldable 3D shapes without losing key features. We describe a new curved folding origami design algorithm, compiling given arbitrary 3D models to 2D unfolded models in G-Code for FDM printers. To demonstrate the Thermorph platform, we designed and printed complex self-folding geometries (up to 70 faces), including 15 self- curved geometric primitives and 4 self-curved applications, such as chairs, the simplified Stanford Bunny and flowers. Compared to the standard 3D printing, our method saves up to 60% - 87% of the printing time for all shapes chosen.